a survey on sensor networks hussein alzoubi [email protected] rami alnamneh...
TRANSCRIPT
Outline
Introduction Communication architecture Protocol stack Conclusion
Introduction
Sensor Networks…low-cost, rapid deployment, self-organizing, and fault tolerance.
Application areas: heath, military, and home. Large number of sensor nodes that are densely
deployed. Nodes use their processing abilities to locally carry
out simple computations and transmit the required and partially processed data.
Ad hoc networks are not suitable for the sensor networks because of their unique features and application requirements.
Communication Architecture
Internet and Satellite
Sink
Task managernode
User
Sensor nodesSensor field
A
B
CDE
Design Factors Fault Tolerance
the ability to sustain sensor network functionalities without any interruption due to sensor node failures because of lack of power, physical damage, or environmental interference.
Scalabilitythe density of sensor nodes can range from few sensor nodes to few hundred sensor nodes in a region.
Production Coststhe cost of sensor node should be much less than $1 in order for the sensor network to be feasible
Hardware Constraints
Power Unit Powergenerator
Location finding system Mobilizer
TransceiverSensor ADC
SensingUnit
ProcessingUnit
Processor
Storage
Continue.. Design Factors
Sensor Network Topology- Predeployment and deployment phase- Post-deployment phase- Redeployment of additional nodes phase
Environmentcan work in different environments.
Transmission Medialinks between nodes can be formed by radio, infrared, or optical media.
Power Consumptionbattery lifetimedesign of power-aware protocols and algorithmsPower consumption: sensing, communication, and data processing
Continue.. Design Factors
Protocol Stack
Application layer
Transport layer
Network layer
Data link layer
Physical layer
Pow
er managem
ent plane
Mobility m
anagem
ent pla
ne
Task m
anagement plane
The Physical Layer
Frequency selection. Carrier frequency generation. Signal detection. Modulation
Binary and M-ary modulation schemesthe binary modulation scheme is more energy-efficient
Low transmission power and simple transceiver circuitry make Ultra wideband (UWB) an attractive candidate.
The Data Link Layer
Multiplexing of data streams. Data frame detection. Medium access and error control. Ensures reliable point-to-point and
point-to-multipoint connections in a communication network.
Medium Access Control Must achieve two goals
- the creation of the network infrastructure- share communication resources between sensor nodes fairly and efficiently.
Can’t be adopted into sensor networks, because- there is no central controlling agent like the base station.- power efficiency directly influences network lifetime in sensor network.
Continue.. The Data Link Layer
Some of the proposed MAC protocols
MAC protocol Power conservation
SMACS and EAR Random wakeup during setup and turning off while idle
Hybrid TDMA/FDMA Hardware-based approach for system energy minimization
CSMA-based Constant listening time for energy efficiency
Continue.. The Data Link Layer
Power saving modes of operationTurning the transceiver off during idling may not
always be efficient due to energy spent in turning it back on each time.
Error controlTwo modes of error control:
- Forward Error Correction, decoding complexities.-Automatic Repeat Request (ARQ), additional retransmission energy cost and overhead.
Best solutions: simple error control codes with low-complexity encoding and decoding
Continue.. The Data Link Layer
Network LayerTask: energy efficient routes
Sink
A (PA=2)
B (PA=2)
C (PA=2) T
D (PA=3)
E (PA=1)
F (PA=4)
α
1=1
α
α
α
αα
α
α
α
α 5=2
3=2
4=2
2=16=2
7=1
8=2
9=2
Route 1: Sink-A-B-T, total PA=4, total α = 3 Route 2: Sink-A-B-C-T, total PA=6, total α = 6Route 3: Sink-D-T, total PA=3, total α = 4Route 4: Sink-E-F-T, total PA=5, total α = 6
Approaches:• Minimum PA route: route 4• Minimum Energy (ME) route: route 1• Minimum hop (MH) route: route 3• Maximum minimum PA node route: route 3
Data Aggregation, data fusion
AB C
DE
FG
Sink
Continue.. Network Layer
Routing techniques
Floodingeach node receiving a data or management packet repeats it by broadcasting.
Gossipingsend the incoming packets to a randomly selected neighbor.
Continue.. Network Layer
Sensor Protocols for Information via Negotiation (SPIN)
Step 1
ADV
Step 2
REQ
Step 3
DATA
Step 4
ADV REQ
Step 5 Step 6
DATA
Continue.. Network Layer
Sequential Assignment Routing (SAR) Creates multiple trees where the root of each tree is a one-hop neighbor from the sink.
Low-Energy Adaptive Clustering Hierarchy (LEACH)Forms clusters to minimize energy dissipation.
Directed diffusionSets up gradients for data to flow from source to sink during interest dissemination.
Continue.. Network Layer
Transport Layer
Transport layer protocols are still unexplored: they may be purely UDP-type protocols, because each sensor node has limited memory and power.
The Application Layer Sensor Management Protocol (SMP)
makes the hardware and software of the lower layers transparent to the sensor network management applications. System administrators interact with sensor networks using SMP.
Task Assignment And Data Advertisement Protocol (TADAP)provides the user software with efficient interfaces for interest dissemination.
Sensor Query and Data Dissemination Protocol (SQDDP)provides user applications with interfaces to issue queries, respond to queries and collect incoming replies.
Conclusion
The flexibility, fault tolerance, high sensing fidelity, low cost, and rapid deployment characteristics ofsensor networks create new and exciting application areas for remote sensing.
Questions?
Thank you!